Hi.. Great tool, thanks for building this.
I've been sorting through about 10k songs I have and as I've been doing this I have run into a rather uncommon event as I've been updating the artwork. What happens is after I add the artwork to the file and save it to "Cover.jpg" in the album directory, it won't update the album artwork. The individual tracks have the artwork.
What has worked in a workaround sometimes is if I change the album artist for the entire set of tracks to something different, then it will show the album artwork. The artwork is whatever is pulled down typically from the Internet Search and Copy Picture.
Example:
Elemental by Tears for Fears
Properly setup with Album artwork as "Cover" artwork in the Artwork section. All the tracks are setup the same for artwork, artist and album artist.
I change the album artist to "Tears for Fears 2" and instantly the artwork shows up for the Album section.
If I change it back to "Tears for Fears" it disappears.